Solid State Lighting (SSL) light bulb assemblies, e.g. Light Emitting Diode (LED) based light bulb assemblies, are expected to replace GLS (General Lighting Service) or incandescent lamps. SSL devices typically comprise a driver circuit and/or power converter in order to convert electric power from a line voltage supply to electric power suitable for an SSL light source comprised within the SSL device (e.g. an array of LEDs).
The driver circuit for an SSL device should be configured to convert the AC line voltage into the possibly constant load voltage and the possibly constant load current. In particular, the driver circuitry should be configured to control the load voltage and the load current such that the SSL device does not flicker in a manner which is visible to the human eye. Such a visible flicker may occur at a frequency of 100 Hz (for an alternating line voltage at a frequency of 50 Hz) or at a frequency of 120 Hz (for an alternating line voltage at a frequency of 60 Hz). Such flicker may be due to the sinusoidal waveform of the alternating line voltage which falls below the required minimum on-voltage Von of the SSL device within each half-wave of the sinusoidal line voltage. As a result, the SSL device is switched off at a frequency of 100/120 Hz, thereby creating an annoying flicker effect of the light source (i.e. of the SSL device).